1. Field of the Invention
In one aspect this invention relates to vehicle lighting systems. In a further aspect this invention relates to a vehicle interior lighting system with emergency backup power.
2. Prior Art
The present dome lights in military vehicles are a source of infrared radiation which is in turn a source of danger from enemy or terrorist forces since most military operations are equipped with at least some form of rudimentary infrared sensing devices. The more sophisticated detection systems can use the infrared radiation from a vehicle both as detection and targeting means. Thus, it is in the interest of troop safety to minimize the infrared signature emanating from the interior of a vehicle. The present interior, dome light structures use incandescent lamps as a light source. Such lamps create a high infrared signature, have high current requirements on the order of 500 milliamperes and have a relatively short life on the order of 500 hours. To ameliorate the signature problem, present military vehicles use blackout filters on interior dome lights when operating in a blackout mode. This structure requires carrying and using a separate filter and creates a possible hazardous condition if the filter is not deployed. In a hostile zone failure to properly deploy blackout filters can endanger the vehicle and occupants.
It would be desirable to have a dome light system that is designed to have a consistent low infrared signature with improved lamp life and low current requirements. It would be a further advantage to have a backup power source for the passenger compartment lighting that could allow the dome light to function if there is a loss of power from the vehicle electrical supply. This would allow personnel to locate their weapons and exit the vehicle even when there is a loss of power.